* crypt/crypt-private.h: Include stdbool.h.

(_ufc_setup_salt_r): Return bool.
* crypt/crypt-entry.c: Include errno.h.
(__crypt_r): Return NULL with EINVAL for bad salt.
* crypt/crypt_util.c (bad_for_salt): New.
(_ufc_setup_salt_r): Check that salt is long enough and within
the specified alphabet.
* crypt/badsalttest.c: New file.
* crypt/Makefile (tests): Add it.
($(objpfx)badsalttest): New.

ChangeLog

@@ -1,3 +1,16 @@
+2012-10-10  Alexandre Oliva <aoliva@redhat.com>
+
+	* crypt/crypt-private.h: Include stdbool.h.
+	(_ufc_setup_salt_r): Return bool.
+	* crypt/crypt-entry.c: Include errno.h.
+	(__crypt_r): Return NULL with EINVAL for bad salt.
+	* crypt/crypt_util.c (bad_for_salt): New.
+	(_ufc_setup_salt_r): Check that salt is long enough and within
+	the specified alphabet.
+	* crypt/badsalttest.c: New file.
+	* crypt/Makefile (tests): Add it.
+	($(objpfx)badsalttest): New.
+
 2012-10-09  Maxim Kuvyrkov  <maxim@codesourcery.com>
 
 	* NEWS: Add entry for BZ #14602.

crypt/Makefile

@@ -28,7 +28,7 @@ extra-libs-others := $(extra-libs)
 libcrypt-routines := crypt-entry md5-crypt sha256-crypt sha512-crypt crypt \
 		     crypt_util
 
-tests := cert md5c-test sha256c-test sha512c-test
+tests := cert md5c-test sha256c-test sha512c-test badsalttest
 
 include ../Makeconfig
 

crypt/badsalttest.c

@@ -0,0 +1,86 @@
+/* Test program for bad DES salt detection in crypt.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <crypt.h>
+
+static const char *tests[][2] =
+  {
+    { "no salt", "" },
+    { "single char", "/" },
+    { "first char bad", "!x" },
+    { "second char bad", "Z%" },
+    { "both chars bad", ":@" },
+    { "un$upported algorithm", "$2$" },
+    { "unsupported_algorithm", "_1" },
+    { "end of page", NULL }
+  };
+
+static int
+do_test (void)
+{
+  int result = 0;
+  struct crypt_data cd;
+  size_t n = sizeof (tests) / sizeof (*tests);
+  size_t pagesize = (size_t) sysconf (_SC_PAGESIZE);
+  char *page;
+
+  /* Check that crypt won't look at the second character if the first
+     one is invalid.  */
+  page = mmap (NULL, pagesize * 2, PROT_READ | PROT_WRITE,
+	       MAP_PRIVATE | MAP_ANON, -1, 0);
+  if (page == MAP_FAILED)
+    {
+      perror ("mmap");
+      n--;
+    }
+  else
+    {
+      if (mmap (page + pagesize, pagesize, 0,
+		MAP_PRIVATE | MAP_ANON | MAP_FIXED,
+		-1, 0) != page + pagesize)
+	perror ("mmap 2");
+      page[pagesize - 1] = '*';
+      tests[n - 1][1] = &page[pagesize - 1];
+    }
+
+  for (size_t i = 0; i < n; i++)
+    {
+      if (crypt (tests[i][0], tests[i][1]))
+	{
+	  result++;
+	  printf ("%s: crypt returned non-NULL with salt \"%s\"\n",
+		  tests[i][0], tests[i][1]);
+	}
+
+      if (crypt_r (tests[i][0], tests[i][1], &cd))
+	{
+	  result++;
+	  printf ("%s: crypt_r returned non-NULL with salt \"%s\"\n",
+		  tests[i][0], tests[i][1]);
+	}
+    }
+
+  return result;
+}
+
+#define TIMEOUT 5
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"

crypt/crypt-entry.c

@@ -27,6 +27,7 @@
 #include <stdio.h>
 #endif
 #include <string.h>
+#include <errno.h>
 
 #ifndef STATIC
 #define STATIC static
@@ -108,7 +109,11 @@ __crypt_r (key, salt, data)
   /*
    * Hack DES tables according to salt
    */
-  _ufc_setup_salt_r (salt, data);
+  if (!_ufc_setup_salt_r (salt, data))
+    {
+      __set_errno (EINVAL);
+      return NULL;
+    }
 
   /*
    * Setup key schedule

crypt/crypt-private.h

@@ -26,6 +26,7 @@
 #define CRYPT_PRIVATE_H	1
 
 #include <features.h>
+#include <stdbool.h>
 
 /* crypt.c */
 extern void _ufc_doit_r (ufc_long itr, struct crypt_data * __restrict __data,
@@ -36,7 +37,7 @@ extern void _ufc_doit_r (ufc_long itr, struct crypt_data * __restrict __data,
 extern void __init_des_r (struct crypt_data * __restrict __data);
 extern void __init_des (void);
 
-extern void _ufc_setup_salt_r (const char *s,
+extern bool _ufc_setup_salt_r (const char *s,
 			       struct crypt_data * __restrict __data);
 extern void _ufc_mk_keytab_r (const char *key,
 			      struct crypt_data * __restrict __data);

crypt/crypt_util.c

@@ -595,24 +595,56 @@ shuffle_sb(k, saltbits)
 }
 #endif
 
+/*
+ * Return false iff C is in the specified alphabet for crypt salt.
+ */
+
+static bool
+bad_for_salt (char c)
+{
+  switch (c)
+    {
+    case '0' ... '9':
+    case 'A' ... 'Z':
+    case 'a' ... 'z':
+    case '.': case '/':
+      return false;
+
+    default:
+      return true;
+    }
+}
+
 /*
  * Setup the unit for a new salt
  * Hopefully we'll not see a new salt in each crypt call.
+ * Return false if an unexpected character was found in s[0] or s[1].
  */
 
-void
+bool
 _ufc_setup_salt_r(s, __data)
      const char *s;
      struct crypt_data * __restrict __data;
 {
   ufc_long i, j, saltbits;
+  char s0, s1;
 
   if(__data->initialized == 0)
     __init_des_r(__data);
 
-  if(s[0] == __data->current_salt[0] && s[1] == __data->current_salt[1])
-    return;
-  __data->current_salt[0] = s[0]; __data->current_salt[1] = s[1];
+  s0 = s[0];
+  if(bad_for_salt (s0))
+    return false;
+
+  s1 = s[1];
+  if(bad_for_salt (s1))
+    return false;
+
+  if(s0 == __data->current_salt[0] && s1 == __data->current_salt[1])
+    return true;
+
+  __data->current_salt[0] = s0;
+  __data->current_salt[1] = s1;
 
   /*
    * This is the only crypt change to DES:
@@ -646,6 +678,8 @@ _ufc_setup_salt_r(s, __data)
   shuffle_sb((LONGG)__data->sb3, __data->current_saltbits ^ saltbits);
 
   __data->current_saltbits = saltbits;
+
+  return true;
 }
 
 void